1. FIELD OF THE INVENTION
The present invention relates, in general, to magnetocaloric equipment, and particular, to a new and useful magnetocaloric device which is capable of inducing electrical power and producing a refrigeration effect.
The magnetocaloric effect, or its reverse, has up until now only been used to achieve very low temperatures that are close to absolute zero.
Magnetocaloric energy conversion opens up fantastic possibilities if one considers that it can utilize or convert omni-present energy, namely, the environmental heat from air, water and earth, right down to the heat occurrences in polar regions, i.e., down to minus 100.degree. C., into electrical energy, and this is permanently available around the clock. Such low temperature conversion is only possible, however, with the aid of materials which display extraordinary magnetocaloric and caloric properties, in particular, magnetic circuits.
In the present invention, the physical property is utilized wherein certain materials, in particular, monocrystalline metamagnetic materials, suddenly become ferromagnetically conductive once their critical threshold field intensity has been exceeded. Once the field intensity falls slightly below this critical threshold, these materials just as suddenly return to their antiferromagnetic state. They are thus "ideal magnetic switches".
These alterations in the magnetic state, or phase transitions of metamagnetic materials, are accompanied by, and connected with, distinctive magnetocaloric effects. Sources: Zeitschrift fur angewandte Physik, April 1962, Heft 4, Prof. Eckhart Vogt, Phys. -Institut Universitat Marburg "Metamagnetismus"; and Fiz. Tverd. Tela (Leningrad) 21, 2808-2810 (Sept. 1979) S. A. Nikitin, A. S. Andreenko and V. A. Pronin, "Magnetocaloric effect and magnetic phase transitions in a dysprosium single crystal".